You observe three carts moving to the left. Cart A moves to the left at nearly constant speed. Cart B moves to the left, gradual
ly speeding up. Cart C moves to the left, gradually slowing down. Which cart or carts, if any, experience a net force to the left? Cart A Cart C Cart B
For cart A speed is constant therefore there is no acceleration because acceleration is rate of change of velocity
thus there is no net force
For cart B there is change in velocity in the left direction , so there is net acceleration towards left
so there is net force in the left direction
For cart C there is decrease in velocity i.e. negative acceleration or deceleration . Therefore there is a net force towards right which opposes the motion
Transverse waves occur when a disturbance causes oscillationsperpendicular (at right angles) to the propagation (the direction of energy transfer). Longitudinal waves occur when the oscillations are parallel to the direction of propagation.